It has long been known that mammals, when confronted with bacterial or viral infections, exhibit efforts at self-healing which are initiated by a complex physiological network referred to as the immune system. The immune system operates in response to a challenge to the mammalian system by initially recognizing the presence of a foreign organism or pathogen within the animals body. This is followed by an attack on the foreign organism by the T-cells, B-cells and other "killer" cells of the mammalian system. This immune response functions or is "turned on" by a variety of immune system regulators which function to selectively activate the various aspects of the immune system depending upon the type of insult confronting the subject animal.
A substantial component of the immune system is a group of structurally related glycoproteins contained within the blood and extra cellular fluids collectively known as immunoglobulins. Five immunoglobulin classes have been identified and are denominated as immunoglobulin G (IgG), IgM, IgA, IgD and IgE. The basic structural unit of each immunoglobulin class consists of two pairs of polypeptide chains joined by disulfide bonds. The five classes of immunoglobulins have different biological properties and different distributions in the body. The structure responsible for the biological properties of each immunoglobulin class is located on that part of the immunoglobulin molecule which is unique for each class--the Fc fragment. While some antibodies are produced at all times in normal animals, specific antibodies--a unique subset of immunoglobulins--may be produced only in response to specific antigenic stimulation.
IgG is the major antibody class in normal mammalian systems and forms about 70% of the total immunoglobulin. IgG is evenly distributed between intra- and extravascular pools. It is the first major antibody of secondary immune responses and the exclusive antitoxin class. IgG is a monomeric protein and can be divided into four sub-chains--two heavy chains and two light chains. Taking the four sub-chains together each IgG molecule consists of one H.sub.2 L.sub.2 unit with a molecular weight of approximately 140,000 Daltons. Molecules of the IgG class are actively transported across the placenta and provide passive immunity to the newborn infant at a time when the infant's immune mechanisms are not developed.
The remaining four immunoglobulin classes are more narrow components of the immune system.
IgM is the first immunoglobulin class produced by the maturing fetus. IgM does not normally cross the placenta from the mother to fetus, but may be produced actively by the fetus prior to birth, especially if the fetus has been exposed to antigens by infection. IgA is found in relatively small amounts in serum and tissue fluids, but is present in high concentrations in external secretion such as saliva, tears, and bronchial secretions. IgE is also present in very low concentrations and appears to be associated with the histamine response. The last immunoglobulin class IgD is present in very low concentrations in the serum. IgD appears to be related to stimulating immature lymphocytes to multiply and to differentiate and to secrete antibodies of other classes. Therefore, it appears that all immunoglobulin classes are important in the immune systems of mammals.
Modulation of the immune system to effect greater response to foreign agents has been an area of interest for some years. The development of specific antibodies through vaccination has long been utilized to provide mammals with long term immune defense mechanisms to specific micro organisms forms.
Recent efforts in immunology have been directed towards the utilization of the immune system regulating molecules themselves to provide increased immune system activity. It is believed that through the use of immune regulating or immune modulating molecules that a state of general hyperactivity of the immune system is induced which may be useful in combating an infection in a mammal challenged by a micro organism. It is believed that such as induced state of general immune hyperactivity would result in a therapeutic response to the challenge. This might be viewed as just the opposite of the vaccination type response which produces a specific long term immunity. If such a non-specific immune response could be initiated at will it could be utilized to either act alone or in conjunction with a conventional treatment directed towards the etiological agents. Such a mechanism could be based upon activation of phagocytic cells which are capable of responding to a wide range of infectious agents. It may also be that the T-lymphocytes, which are major mediators of the overall immune response, may act to enhance the operation of non-specific cellular immunity even though the T-lymphocytes themselves are a part of the specific immune response.
Therefore, it is an object of the present invention to provide a means for modulating the immune response in mammals afflicted with disease.
Another object of the present invention is to provide a means for enhancing the ability of conventional anti-micorbial medicaments by providing a concomitant stimulation and potentiation in the mammalian immune response.
Yet another object of the present invention is to provide a means of stimulating the immune response in mammals to heighten the mammals ability at self-heating when challenged by an infectious agent.
The above and further objects and novel features of the invention will more fully appear from the following description and the examples contained therein.